Hey. I'm running about 950 whippled hp through my XR drive on my 27 Eliminator Daytona. I run on a freshwater lake so no air time, very easy on sticks, etc. The lower is recently rebuilt. I've just removed the top cap and can see that the horizontal gear coming into the upper is pitting and small chunks of metal are afloat. I can't really see the teeth on the first top vertical gear, but am I right that if I replace the pitted one I replace the whole set, no matter what the condition? Also, I read a lot of 7 to 8 year old threads about how crap the replacement XR gears are from merc, some people only getting 10 hours out of new ones vs. 100 old. Have they got that sorted out? Is there any way to avoid certain years of manufacture if that is the case? Who sells the cheapest OEM replacements? Thanks!

Generally, the'll both be pitted, what won't be is whichever is the reverse gear, it will most likely have little wear
at all, mercury sells the pinion by itself, but doesn't sell the drivens seperarely, IMCO however does, IMCO and the Bravo shop sell the internal bearing for the driven gear, merc doesn't.... a complete upper gear set is approaching $ 2k, you can do a pinion and a driven from IMCO for around $. 1350

Jay, this is extremely helpful - you just saved me 1000$(CDN) - thanks.

As the XR can run Right and Left rotation with same power,is it posible to change the Props and drive in Left Rotation?
I think soem times if this will work!?
Best regards
Michael

yes, you can install an opposite rotation prop on and run the shifter in reverse fashion... the drive knows no difference

I think I have a good driven gear, if you are interested I'll sell it for a couple hundred dollars plus the ride. Let me know, and if interested, I'll find it, and send you some pictures, but I remember it being in good condition.

Wow. Did you make good on the bad carburetor deal?

If you're pushing that much power through an XR, you should talk to George at All American Drive. He has redesigned some of the shafts and bearings to make them a lot stronger. Had him do my drive and he has hundreds of broken shafts due to their poor design and insufficient bearing size.

The gears are insufficient no matter what, I rarely hear about XR shafts beaking...standard bravos break shafts.

When was talking to Mr. Gadgets about shafts, he told me there are two people that make them, Merc and Imco. The Imco is drilled in one pass all the way through, the Merc in two passes, that can create a ridge inside and cause a weak spot in that area. AAD may make their own shafts, but I've also heard a lot of guys claiming they make their own gears, and we know that isn't true.

As JRider said, the biggest issue is the gears, then IMO the clutch shaft. All of the shafts inside an XR are the same as a standard bravo except for the prop shaft. As for the bearings, you can't improve the bearings in the gear, you can't make the bearings between the gear and the shims any bigger, and there is no need to improve the caged bearings on the clutch shaft, so I'm curious what bearings AAD is improving?